Ruling engine



Nov. 24,'1942. R. R. FINN RULING ENGINE Filed Maren 18, 1941 3Sheets-Sheet 1 Nv.24, 1942. R, R, FINN 2,303,299

RULING ENGINE Filed Marrshv 18, 1941 3 Sheets-Sheet jim I" Il 1X4. m f/24 //J Nov; 24, 1942. R. R. FINN 2,303,299

` RULING ENGINE Filed March 18, 1941 3 fSheets-Sheet 3 Patented Nov. 24,1942 UNITED STATES PATENT OFFICE RULING ENGINE Robert R. Finn,Springfield, Vt.

Application March 18, 1941, vSerial No. 383,971

14 Claims.

This invention relates to ruling machines commonly called ruling enginesand has for an object to provide such a machine of relatively low costbut which is capable of high accuracy.

More particularly this invention has for an object the production of aruling machine of sufficient accuracy so that it may be used for rulingdiffraction gratings. A diifraction grating possesses a highly polishedoptically flat reflecting surface with closely spaced parallel linesserving to break up any light applied to the surface. The spacing of thelines must be extremely accurate and there may be on the order of 15,000to 20,000 lines per inch. Beside requiring a machine of very highaccuracy to rule satisfactorily for this purpose, it is necessary tomount such machines on pedestals set into the ground in Iplaces awayfrom traffic or other disturbances and to house the machines in constanttemperature enclosures.

Ruling machines are commonly provided with fed screws for spacing thelines, but the manufacture of such screws of suicient accuracy forruling diifraction gratings presents Very great obstacles and there isno way to test the accuracy of the screw except by trial in making thegratings. The greater the length of rthe screw, the greater are thesedifficulties. Moreover, intermittent feed devices for such screws affordother sources of error most difficult to overcome.

A further object of this invention, therefore, is to provide feedmechanism of a simple nature which requires no lead screws orintermittent rotation of feed elements.

A still further object of this invention is to overcome as much aspossible the variable effects of friction and incident to the use oflubricants, which latter are entirely avoided in accordance with thisinvention. 1

For a more complete understanding of this invention, reference may behad to the accompanying drawings inwhich Figure 1 is a top plan View ofone embodiment.

Figure 2 is a right hand end elevation of the same.

Figures 3 to 7, inclusive, are sectional views on the correspondinglynumbered section lines of Figure 1.

Figure 8 is a detail section on line 3 3 of Figure 7, and

` Figure 9 is a detail section on line 8 9 of Figure 5.

Referring to the drawings, the ruling machine cr engine comprises a flatsupport I to the top 55 it is provided with means for supporting thework to lbe ruled. As shown this work support comprises an endupstanding wall member 6 secured to the work carriage and spacedtherefrom` across bar 1. This cross bar is adjustably securedvertically, with respect to the carriage Il by means of end Iadjustingstuds I0 having their lower ends threaded into the upper face of theVcarriage 4 at opposite sides and carrying nuts Il above and below thecross bar l.

v The Work herein shown as a diffraction grating I2 is supportedhorizontally between a pair ofl adjusting screws I3 spaced apart andnear the ends of the bar 'I and a single central adjusting screw I4 inthe bar 3. The work I2 rests upon three leveling screws I5 in threadedopenings through the carriage 4 and accessible from beneath foradjustment. By this means the optically fiat top surface of the Work maybe lined up properly with relation to the marking tool, which will laterbe described, so that markings of uniform depth may be produced over thevarious portions of the surface of the grating.

The two carriages 4 and 5, carriage 5 being termed herein a stopcarriage, are guided for linear motion by the guide bar 2, the guide barl 3 being positioned spaced from the guide bar 2 so as to permit motionof the carriages along the bar 2, but without substantial lost motion.These carriages 4 and 5 are each mounted on three point roller bearingsof a type Which require no lubrication. For this purpose accuratelyformed rails 20 are positioned inwardly'of each of the bars 2 and 3 andon each of these rails is positioned a -ball 2| for` each of the `slides4 and 5. Substantially centrally between the guide .bars 2 and 3r `arerails 22 for supporting a central ball 23 for each of these carriages.The top faces of these rails 20 and 22 are accurately at and thecarriages rest on the balls 2| and 23 by gravity.

Each carriage is provided with means independent of the other tending tofeed it in one direction along the guide rail 2. -Tothis end each of thecarriages has a post 25 depending therefrom to which is attached one endof a cord or cable 26. The posts are offset Vlaterally'from each otherso that the cords 26 do not conflict with each other and these cords arebrought over spaced pulleys 2'I journaled in a bracket 28 secured to oneedge of the support I., Suitable Carweights (not shown) are hung to thelower ends of these cords or cables 26. A stop screw 29 limits theextent of motion of the adjacent carriage.

Means are provided for connecting the carriages 4 and 5 for a limitedlost motion, the extent of this lost motion determining the extent offeed of the work carriage 4 at each feeding or indexing action, and thusdetermining the space between the lines ruled on the grating. This lostmotion connection is illustrated best in Figures 'I and 8. One of thecarriages 4 and 5, herein shown as the carriage 4, has secured tov itstop face as by screws 29 a U shaped yoke member 3|), this yoke memberhaving a downwardly turned end 3| projecting over the rear edge of theother carriage, such as 5. This other carriage is provided with anupstanding abutment bracket 32 which extends above its upper face and inbetween the portion 3| of the ment as shown comprises a pair of screws40 Y extending through holes in the abutment 32 and threaded into themember 38 by whichthe member 38 may be drawn toward the abutment 32, anda pair of screws 4| threaded through the member 38 and having theirinner endsengaging the adjacent face of the abutment 32 to limit theextent of such drawing movement or for. forcing the member 38 away fromthe abutment 32. By this means the member 38 may be spaced accuratelyfrom the member 32, thus to adjust the amount of lost motion permittedbetween the carriages 4 and 5, this'` lost motion occurring in bothdirections between the members 4and 5. At one limit of motion theabutment 32 engages the ball 36 and presses it into contact with theportion 3|, and at the other limit of lost motion the member 38 pressesthe ball 31- into contact with the part 33.

Means are provided for alternately andv independently clamping thecarriages 4 and 5 against motion, and alternately releasing one of.these carriages while the other is clamped and then releasing the otherwhile the one is clamped, thereby permitting a step by step or indexingfeed motion of the work carriage, eachV time by an amount equal to thelost motion betweenthe two carriages. In order that this alternateholding and stopping of the motion of the carriages may be accuratelyaccomplished, means are provided for engaging one side of each of thesecarriages and clamping it against the guide bar 2, which is veryaccurately formed, and the carriages themselves are of sufficient lengthso that they cannot be tilted appreciably during the course of theirfeed motions, or while they are clamped or released.

The clamping means shown comprises a clamp bar 50 which is seated in arecess 5| in the inner face of the guide bar 3. As shown best in Figure1, this bar 50 is secured centrally as by the screw 52 within its recessand on each side of this screw it is slotted inwardly as at 53 toprovvide weakened portions which may flex when 5| Thesel ends of the bariii!y are widened slightly to form brake shoe portions 54 which may bepressed against the edges of the carriages 4 and 5 at suitable times tohold these carriages against motion. The inherent springiness of the bar58 is suflicient to normally hold the shoe portions 54 out of clampingcontact with its respective carriage, but they may be forced intoclamping position by the motion of the thrust bars 55 and 56. Bar 55 isshown in Figure 1 as being in position to actuate the forward shoe 54 tostop the motion of the stop carriage 5, while the bar 56 similarlycontrols the application of the other shoe 54 to stop the motion of thework carriage 4. As shown in Figure 4, the thrust bar 55 is extended toa considerable distance from the guide bar 3 to the side of the supportwhere this support has fixed thereto a bracket 6|).Y This bracket 60 isprovided with driving means for controlling the thrust bars 55 and 56,and also for producing cross motion of a tool carrier as will later morefully appear.

As shown in Figure 4, the outer end of the thrust bar 55 is providedwith a head 6I riding in a guide opening 62 in a wall portion 63upstanding from the bracket 66, and against the outer end of this head6| there bears a coil spring 64 housed within a hollow plug 65 threadedinto the outer end of the guide opening 62. A screw 66 threaded throughthe rear end of the plug 65 and having a head engaging the outer endofthe spring 64 serves to adjust the pressure exerted by the spring 64 onthe thrust rod 55' thus to determine the pressure exerted on thecorresponding brake shoe 54V and thereby the holding force exerted toprevent the motion of the carriage 5. This pressure should be sufficientto prevent motion of this slide underv the impact which this slide mayreceive in arresting the motion of the carriage 4 when thiscarriage hasbeen released. The means for applying pressure to the thrust rod 564 maybe similar to that described for the thrust rod 55. These thrust rodsare retracted at suitable times to re,- lease their respective carriagesand for this purpose the bracket 68 carries pivoted, as on a pin 61, arelease dog 68 for each rod. The. lower corner 69 of one of theserelease dogs may impinge upon and retract the head 6| of the thrust rod55 and this may be effected by impingement on a nose portion 15 thereofof a roller 10 journaled in a slot 1| in a disk 12 keyed to an actuatingshaft 13. This actuating shaft is journaled in spaced bearings 14upstanding from the bracket 60 and carries two of these disks 12arranged in different angular positions thereon, one for each of thethrust rods 55 and 56, so that as this shaft 13 is rotated as by adriving belt 18 engaging a drive pulley 19 fixed to the shaft 13, thethrust rods 55 and 56 are alternately actuated in a sequence as follows:

Assuming that the carriages 4 and 5 are in the position shown in Figure'1, both carriages being then held by their respective thrust rods 55and 56 and shoes 54 in xed position and with the abutment 32, the ball36, and the yoke member 3| in engagement, the thrust rod 56 isthenretracted so as to release the carriage 4 which is then pulled towardthe carriage 5 until the ball 31, the portion 38, and the yoke portion33 are in engagement, the lost motion then occurring between theabutment 32 and the portion 3| of the yoke member, This produces aslight feeding motion of the carriage 4 and the thrust rod 56 is thenallowed to be pressed forward by its spring, clamping the carriage inthisv new posi-- tion. While both carriages are clamped, the tool iscaused to traverse the work in operative direction to rule it and afterthis traverseI has been effected, the thrust rod 5.5 is retracted,allowing the stop' carriage 5 to feed forwardly until it reaches theposition shown in Figure 7 with the lost motion taken up between theabutment 32 and the yoke member 3| and occurring between the member 38and the yoke portion 33. The carriage is then clamped by the action ofits spring pressed thrust rod 55 and the carriage 4 is thereafterunclamped to allow this carriage to be moved bythe action of its movingmeans for another incremental or indexing feed motion preparatory to thenext ruling motion of the tool. It will thus be seen that the extent ofthis incremental feed motion is in no way dependent upon any feed screwsor intermittent rotating feed mechanism which are exceedingly difficultto accurately construct, but the extent of the motion of each feed isdetermined by the extent of the lost motion connection between thecarriages 4 and 5 which can be accurately determined and be the same foreach actuation.

The tool 89 for ruling the work is carried by a carrier 8| mounted formotion transverse to the motion vof the carriages yl and 5. This carrier8|, as shown best in Figure 5, is centrally cut away as at 82 on itsunder face so as to clear the work support and the work on the carriage4, and it is supported for transverse motion on a three point rollingsupport. Two of these supporting points as shown comprise balls 83 whichare supported between pairs of rods 84 and 85 of circular cross section,the rods 85 being secured in a channel 86 in the wall member 9| and therods 84 being secured in a similarly opposed channel 81 in the lowerface of the carrier 8|. By supporting the balls in this manner they areprovided with line contacts with their bars 84 and 85, and in order thatany inaccuracies tending to rock the carrier about these balls shallhave as little effect as possible on the accuracy of ruling, the tool 89is arranged with its ruling point in line with the common axis of theballs 93. A third rolling contact for supporting the carrier 8| isbetween an upstanding portion 90 of the carrier and the Wall member 9|extending upwardly from the support and as shown being in the form of abracket secured as by screws 92 to the top face of the support Thecentral portion of this member 9| is cut away as at 93 to bridge overthe guide bars 2 and 3 and the work carriage 4 with the work supportedthereon. This third rolling Contact comprises the ball |99 locatedbetween accurately fixed members' |0| and |02 carried by the portions 8|and 9|, respectively. The ruling tool itself isV shown as carried by athreaded plug |04 adjustably threaded into a yoke member |95` havingball trunnions |96 engaging in the ends of oppositely disposed plugs |91and |98 in spaced depending flanges |99 and ||9 of the carrier.

As shown best in Figure 5, this plug |04 is arranged at one side of thetrunnion axis afforded by the balls |96 so that by rocking the yokemember |95 the ruling tool can be lifted from the work or allowed tobear thereon. Means are provided by which during one direction'oftraverse of the carrier, the ruling tool is in operative engagement withthe work and during the other direction of traverse it is out ofoperative position. Mechanism for doing this is shown best in Figure 5.Carried by the yoke member ||l5on the opposite side of the pivot fromthe tol is ari abutment member ||2 in alinement with which a pin 3 isvertically slidable through` the carrier r|32. normally held elevated'asby a spring ||4 reacting between its head ||5 and the upper face ofthe'i carrier 82 and above this head thereis positioned a bar ||6axially slidable through` openings in a pairofsupports upstandingV fromthe carrier 82. The lower face of this bar H5 is provided with a notch||8 and whenv this bar is inthe axial position shownin Figure 5, thisnotch |8 is above the pin ||4 so that this pin is retracted and theruling tool is in its operative position.V By moving the bar ||6axially, however, the notch 8 may be brought out of alinement with thehead of the pin H3, causing this pin to `be depressed and raising theruling tool into inoperative position. As theV carrier is moved from oneto the other side, this bar H6 alternately impinges on adjustable stopsmounted in brackets |2| secured to the wall member 9|, so that' the barH6 is moved alternately into two axial positions, in one of which itallows the ruling tool to engage the work and in the other of which itholds the ruling tool out of such engagement.

'Means are provided for reciprocating this carrier to move the tool backand forth across the work. As shown this means comprises` a crank disk|25 secured to one end of the shaft 13 and having a cross slot |25within which may be adjustablysecured a crank pin |21 so as to adjustthe amplitude of motion of the tool carrier. This crank pin is connectedthrough an arm |28 with a slide |29 having a slot 3&1 therethroughthrough which the shaft 13 projects. 'I'his slide |29 is mounted'onsuitable ways in a guide portion |32 of the bracket 90 and its inner endis connected through a relatively light thrust rod |33 to the carrier83. This thrust rod serves to impart substantially only pull and thrustmotion to the carrier, avoiding substantially en-` tirely any verticalcomponents such as are imparted to the slide |29 through its drivingcrank mechanism. v

While as shown, the stop carriage 5 is in advance of the work carriage4, the direction of motion of these two carriages along the bar 2 isimmaterial, and they might be moved in the opposite direction. For thispurpose a second bracket 23 carrying another pair of pulleys 27 and astop screw 29 is shown as secured to that end of the support adjacent tothe Wall member 9|, and these pulleys would be used to support the cords26 for feed of the carriage .4 in advance of the carriage 5.v Anydesired length of grating within the capacity of the machine may beruled.

From the foregoing description of an embodiment of this invention itwill be evident to those skilled in the art that various changes andmodiications may be made without departing from the spirit or scope ofthis invention.

I claim:

1. A machineof the class described, comprising a pair of carriages,means supporting said carriages for motion in one direction, meansconnecting said carriages together with lost motion in said direction,means for moving said carriages in said direction alternately by theamount of said lost motion, a carrier mounted for motion transverse tosaid direction, means supporting a pair of elements one comprising aWork piece and one comprising a tool, one of said This pin is elementsbeing supportedrlzvy` one of said carriages and the other/ofsaidelements beingsupported by said carrienin, position forl the tool tooperateV on therworknpieey-.during oneof said motions, and vmeansformoving said carrier.

2. Amachine of the class described, comprising a ,work carriage a stopcarriage, means supporting said carriages for motionin a-.commonrectilinear path one carriage being positionedv back of the othercarriage, means independent for said carriages tending to movesaid-carriages forwardly, a toolvcarrier mounted for motion transverseto the motion of said carriages, a tool on said carrier foroperation onWork on said v.work carriage,Y a llost motion connection lbetween saidcarriages, means independent for each carriage for holding itsrespective carriage against motion, means actuating lsaid holding meansalternately to permit motion of one of said carriagesto the extent ofsaid lost motion while the other carriage is stationary and `withaspe'riod When `both carriages are so held, and means acting during.saidA period `to move-said 'carrier to cause said tool to draw a line onthe backA of the other carriage, means independent forsaid carriagesvtending to move said carriages forwardly, a tool carrier mounted formotion transverse to they motion `of said carriages, a tool on saidcarrier for operation oniworlr .on saidV Work carriage, an abutment onone of said carriages, a yoke carried bythe other .of said carriages forengagement with each side of said abutment inthe direction of motionofsaid carriages. and :with apredetermined extent of lost motion in thedirection'of motion of saidcarriages, means independent lforeachcarriage for holding its respective carriage against motion, meansactuating. said holdingmeans alternately to permit motion of one of saidcarriages to the extent of said lost motion While the other` carriage isstationary and with a period when both carriages are so held, and meansacting during said period to move said carrierL to causev said tool todraw a line on the Work.-

4. A machinev of .the classvdescribed,I comprise clamping itsrespectivejcarriage, against said L guide bar, means for alternatelyactuating said,

clamp to release one of said carriages forlmotion by the amount of suchlost motionthrough the action of .its motionproducing means andwhile theother carriage remains clamped and to then clamp said one carriage` andthereafter to release the other carriage for motion along said bar byvthe amount of said lost motion and then to clamp said other carriage,and means acting when both carriages are clamped and between successivemotions of said work carriage to actuate said carrier to cause saidtool-to mark the work.A l

5. In a ruling engine,--a `supportma pair-'of 75' alined carriages eachhaving a. three point rollingcontact with said support, a guideibar,along which said carriages :may move, means individual toeachcarriage-tendingA to4 move said carriages in the-same direction, a lostmotion connectionbetween said carriages, means individual to eachcarriage for clamping the respective carriageY to said guide bar, andmeans actuable to serially actuatesaid clamping means to release oneofsaid carriages for motion equal to said lost motionwhile the othercarriage is clamped and then to release vsaid other carriage for motionequalto said lost motion while said one carriage is clamped, wherebysaid work carriage progresses along said guideway by successive feedincrements each equal to the amount of said lost motion.

6; In ra rulingfengine, a support, a pair of alined carriages eachhaving a three point rolling contact with said support, a guide baralong which said carriages may move, means individual to each carriagetending rto move saidL carriages in the same direction, a llostmotionconnection between said carriages, means individual to eachcarriage for clamping the respective carriage to said guide bary each ofsaidfclamping-means including a spring for applying yclamping pressureof a uniform amountat-each clamping action, and lmeans actuable toy.serially actuate lsaid clamping means to release one of said carriagesfor motion equal to said .lost motion whilel the other carriageisclamped and ythen to release said other carriage for motion equal tosaid lost motion while said one f carriage is clamped,

whereby said work carriage progresses along said guideway by successivefeed increments .each equal to the amount of saidrlostmotion.

7. In a ruling engine, a support-having an upstanding wall portion, acarrier mounted ony said support for motion along said wall portion,said f mounting comprising a threey point rolling'c'ontact, one of saidpoints being located at said wall portion.

8. `In a ruling engine, a support having an upstanding wall portion, acarrier mounted on said support for motion along said wall portion, saidmounting comprising a three pointrollingcontact, one of said pointsbeing located at said Wall portion, at least one ofsaid. contacts'comprising; pairs of rods cylindrical 4in cross section supported inparallel. relation on. said supportr and carrier and a ball interposed'.between said :pairs of rods.

9. In a ruling engine, a support, a 'carrier mounted on said support formotionin one direction, said mounting comprising a three point rollingcontact, at least one vof said contacts comprising pairs of rodscylindrical in cross section supported in parallel relation on-saidsupport and carrier, and a ballinterposedbetween l said `pairs of rods.

10. In a ruling engine, a support, a work carriage mounted on saidsupport for indexing motion in one direction, a wall member upstandingfrom said support and bridging over said work carriage transverse to theline of motion of said work carriage, and a toollcarrier having a toolsupport above said Work carriage, said tool carrier having a two pointbearing on said support,

.one point on each side of said carriage, and a third point bearing onsaid wall member.

ll. In a ruling engine, a support, a work carriage mounted on saidsupport for indexing motion in one direction, a Wall vmember upstandingAfromsaid. support; and; bridging over-said Workv r carriage transverseto the line of motion of said work carriage, a tool carrier having atool support above said work carriage, said tool carrier having a twopoint bearing on said support, one point on each side of said carriage,and a third point bearing on said wall member and a tool having anactive portion in substantial alinement with the points of said twopoint bearing.

12. In a ruling engine, a support, a work carriage mounted on saidsupport for indexing motion in one direction, a wall member upstandingfrom said support and bridging over said work carriage transverse to theline of motion of said Work carriage, a tool carrier having a toolsupport above said work carriage, said tool carrier having a two pointbearing on said support, one point on each side of said carriage, and athird point bearing on said wall member, each of said bearingscomprising a single ball, and a tool having an active portion insubstantial alinement with a common axis of the balls of said two pointbearing.

13. A machine of the class described comprising a support, a workcarriage mounted on said support for indexing motion in one direction, atool carrier mounted on said support for motion transverse to the lineof motion of said work carriage, a tool carried by said carrier inposition to act upon work on said work carriage, said carrier mountingincluding a pair of supporting balls between said carrier and supportspaced in the line of motion of said carrier, said tool when inwork-engaging position lying in substantial alinement with the commonaxis of said pair of balls, means for indexing said Work carriage, andmeans for moving said tool carrier in the intervals between the indexingof said work carriage.

14. In a ruling engine, a support, a carrier mounted on said support formotion in one direction, said mounting including a pair of ballsinterposed between said carrier and support and spaced in the line ofmotion of said carrier, and a tool carried by said carrier with itsactive portion in substantial alinement with the common axis of saidpair of balls.

ROBERT R. FINN.

